Status Boards

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Status Boards
Primary Contact Michael Erskine
Created 11/03/2016
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QR code

Simple means of showing status of Hackspace stuff on web and physical boards.

The driving of the 16 LEDs poses an interesting problem due to the limited number of digital outputs on the NodeMCU: we are looking for a simple low-cost solution so after looking at various ICs to perform the task I decided to throw in another inexpensive micro with plenty of I/O and control it with I2C, serial or similar.

Using a cheap ProMicro for I/O

The NodeMCU can tell the ProMicro what outputs to drive with a simple serial protocol: -

Power Profile

For my first tests I used a cheap 18650 power bank that one would normally use for recharging a mobile phone when off grid. It ran for less than 24hrs but I was not sure of the initial charge. Anyhow, there's no overarching need for this device to be battery powered so I will probably just run it from a spare mains phone charger but it has got me thinking about the power usage so I'm going to learn a little about that:-

  • I'd like a generic current logger that I can attach to various devices - e.g. the SparkFun Low Current Sensor Breakout - ACS712
  • there may be ways of reducing the current draw for the LEDs
  • The NodeMCU - is it a power hog?
  • how efficient is our 5v ProMicro and can we save power by making simple mods and running it at 3.3v